Technical Field
[0001] The present application relates to the technical field of wall-climbing robots, and
in particular to a path planning method for a wall-climbing robot.
Background of the Invention
[0002] A wall-climbing robot has characteristics of a large load and a heavy body, and often
needs to be externally connected with some devices during working. FIG. 1 is a schematic
diagram illustrating a working principle of a robot system. For example, a main operation
mode of a ship derusting robot is to be safely and reliably adsorbed to a surface
of a ship for a derusting operation with a high-pressure water jet module carried.
Meanwhile, since this technology is integrated with wall climbing, derusting and recycling,
the ship derusting robot needs to carry a high-pressure water pipe, a vacuum recycling
pipe and a cable to operate.
[0003] FIG. 2 is a schematic diagram illustrating several types of movement path planning
for a wall-climbing robot. At present, path planning for the wall-climbing robot mainly
includes: straight, N-shaped (Z-shaped) and zigzag path planning. A straight crawling
trajectory is low in efficiency, the robot can only travel in a straight direction,
but cannot crawl back and forth, and for the wall-climbing derusting robot to derust,
it will lead to poor consistency at a connection part of a derusting portion and affect
the overall derusting quality. Operation with an N-shaped (Z-shaped) trajectory also
has the consistency problem at the connection part of the derusting portion, and when
the robot operates according to the N-shaped (Z-shaped) trajectory, the robot needs
to carry out a large-scale steering operation, so that the efficiency is reduced and
high steering performance of the robot needs to be ensured. Although the derusting
portion of a zigzag crawling trajectory has a certain overlapping region, the overall
derusting quality is good and the derusting efficiency is high.
[0004] Due to complex working conditions of a wall surface of the ship, existing path planning
solutions for the robot are basically semi-automated operation, that is, in the N-shaped
(Z-shaped) path planning, the lane changing action needs manual operation. Meanwhile,
when the wall-climbing robot is adsorbed to the wall surface of the ship and travels,
the wall-climbing robot will slide down along the wall surface of the ship under the
action of the gravity of the robot itself, the gravity of the high-pressure water
pipe and the gravity of the recycling pipe. Especially when the wall-climbing robot
travels in a horizontal direction, the robot undergoes a serious tail falling phenomenon,
that is, after the robot travels for a period of time, the whole robot will shift
downwards for a certain distance, resulting that the robot is unable to operate according
to a previously planned path.
[0005] When the wall-climbing robot operates vertically along the wall surface of the ship,
with the increase of a climbing height of the robot, the pipe to be dragged correspondingly
becomes longer, the gravity of the pipe will increase, and the mass of the load of
the robot and a position of its center of gravity will change, resulting in a certain
angle deviation of the robot. With the increase of the distance, the deviation value
will gradually increase, and manual adjustment is required. The lane changing action
tests the experience of operators, and the lane changing distance cannot ensure consistency.
If the lane changing distance is too small, an overlapping area is caused to be too
large and the efficiency is low; and if the lane changing distance is too large, repair
missing regions are caused and need to be repaired, and the operation efficiency is
reduced.
[0006] The related art only considers the operation in a vertical mode and never considers
the operation in a horizontal mode. When the wall-climbing robot performs horizontal
operation along the wall surface of the ship, the robot will undergo the tail falling
phenomenon due to the influence of the gravity of the robot itself and the load, and
the above problems will be more serious.
Summary of the Invention
[0007] In order to solve the above technical problems, the present application provides
a path planning method for a wall-climbing robot. The present disclosure mainly solves
the problems of path planning, vertical face straight walking and automatic lane changing
of the robot, and the robot implements automated operation according to the path planning,
vertical face straight walking and automatic lane changing, so that people are freed
from frequently operating a remote controller and performing real-time monitoring,
and the robot is more intelligent. With the adoption of this solution, the functions
of vertical face straight walking and automatic lane changing of the wall-climbing
robot are realized, so that a whole robot system is more automatic and the work efficiency
is improved.
[0008] The technical solution adopted in the present application is as follows.
[0009] A path planning method for a wall-climbing robot includes following steps:
step 1, establishing a spatial pose model of a wall-climbing robot during a working
process;
step 2, performing statics analysis on the wall-climbing robot, and decomposing a
resultant force G of gravity of the wall-climbing robot itself and gravity of a load
borne by the wall-climbing robot;
step 3, performing kinetics analysis on the wall-climbing robot, and analyzing a crawling
capability and a steering capability of the wall-climbing robot; and
step 4, performing path planning according to analysis results of the crawling capability
and the steering capability.
[0010] Further, the analyzing the crawling capability of the wall-climbing robot in step
3 specifically includes: dividing crawling movement modes of the wall-climbing robot
on a wall surface of a ship into a vertical mode and a horizontal mode.
[0011] Further, the vertical mode includes vertical upward movement and vertical downward
movement, a crawling robot in the vertical upward movement needs to overcome a resistance
moment caused by the gravity of a body and the gravity of the load of the robot and
a resistance moment caused by friction of wheel sets, and when a speed is constant,
a resistance moment of the wall-climbing robot in the vertical upward movement is
greater than a resistance moment in the downward movement.
[0012] Further, the vertical mode is implemented by following steps:
step 301, manually adjusting the wall-climbing robot to a vertical posture, and recording
a current feedback angle α of an inertial measurement unit module; and
step 302, setting a walking distance and a lane changing width of the wall-climbing
robot, and starting, by the wall-climbing robot, automated operation according to
the current feedback angle, with a completed operation area being S*L*N, where S represents
a crawling distance, L represents the set lane changing width, and N represents a
number of lane changing.
[0013] Further, the horizontal mode includes horizontal forward movement and horizontal
backward movement, and in horizontal movement of the crawling robot, the crawling
robot needs to overcome the resistance moment caused by the gravity of the body and
the gravity of the load of the crawling robot and the resistance moment caused by
the friction of the wheel sets.
[0014] Further, in the horizontal mode, due to an influence of gravity Gz, an upward force
Fz is needed for compensation; and
in the horizontal mode, a force balance equation of the crawling robot is as follows:

where Q represents a resultant force of a driving force and a friction force when
the robot moves forward, FZ represents a component of the resultant force in a z axis direction, FX represents a component of the resultant force in an x axis direction, and α is a
set offset angle.
[0015] Further, the horizontal mode is technically implemented by following steps:
step 301', manually adjusting the crawling robot to a horizontal posture, and recording
a current feedback angle α1 of the inertial measurement unit module;
step 302', allowing the crawling robot to move forward a set crawling distance S,
and recording a current feedback angle α2 of the inertial measurement unit module;
step 303', calculating a difference between the two angles αf = α2 - α1, and taking αf as an offset angle set for the crawling robot moving forward the distance S;
step 304', manually adjusting the crawling robot to the horizontal posture corresponding
to the feedback angle α1 again;
step 305', allowing the crawling robot to move backward the set distance S, and recording
a current feedback angle α3 of the current inertial measurement unit module;
step 306', calculating a difference between the two angles αb= α3 -α1, and taking αb as an offset angle set for the crawling robot moving backward the distance S; and
step 307', performing automated operation, by the crawling robot, according to the
offset angles αf and αb measured at two times, with an operation area being S*L*N, where S represents the
crawling distance of the robot, L represents the set lane changing width, and N represents
the number of lane changing.
[0016] Further, the analyzing the steering capability of the wall-climbing robot in step
3 specifically includes:
a rotation speed and a rotation radius of the wall-climbing robot during a steering
process are codetermined by movement directions and speeds of driving wheels, and
the rotation radius directly determines a lane changing distance of the wall-climbing
robot;
when speed directions of two driving wheels are identical, speed directions of wheel
sets on two sides are identical, and a rotation center is located on an outer side
of the wall-climbing robot; and
when the speed directions of the two driving wheels are opposite, the speed directions
of the wheel sets on the two sides are opposite, and the rotation center is located
on an inner side of the wall-climbing robot.
[0017] Further, when the speed directions of the wheel sets on the two sides are identical,
a following formula is obtained:
when the speed directions of the wheel sets on the two sides are opposite, a following
formula is obtained:

where, a point a, a point b and a point c are centers of the wheel sets on the two
sides and the body of the wall-climbing robot, r represents a steering radius of the
wall-climbing robot, which is half of the lane changing distance L, Va and Vb are speeds of the wheel sets on the two sides of the wall-climbing robot, Vc is a speed of the body of the wall-climbing robot, r is the steering radius of the
wall-climbing robot, and B is a distance between the point a and the point b.
[0018] Further, implementation of lane changing by the wall-climbing robot specifically
includes:
calculating the steering radius r of the robot according to the set lane changing
distance L, so as to calculate the speeds Va and Vb of the wheel sets on the two sides of the wall-climbing robot for first steering;
and
starting, by the wall-climbing robot, second steering when a rotation angle of the
first steering reaches 90 degrees, and rotating 90 degrees again in an opposite direction
of the first steering to complete a lane changing action.
[0019] Through the embodiments of the present application, the following technical effects
can be obtained: compared with the existing path planning, according to the present
disclosure, the advantages of Z-shaped (N-shaped) and zigzag path planning are integrated,
operation steps for lane changing are reduced, an overlapping region is reduced and
the operation efficiency is improved. Above all, the automated operation is realized,
and does not rely on the experience of the operator. The tail falling phenomenon is
avoided by rotating a certain compensation angle, so that the robot can walk in a
horizontal line instead of a previous curve in the horizontal mode, and inside path
navigation and automatic lane changing can be better realized.
Brief description of the Drawings
[0020] In order to more clearly explain the technical solutions in embodiments of the present
application, the following will make a brief introduction to the drawings that need
to be used in the description of the embodiments or the related art. Obviously, the
drawings in the following description are some of embodiments of the present application,
and for those skilled in the art, other figures can also be derived from these figures
without creative labor.
FIG. 1 is a schematic diagram illustrating a working principle of a robot system.
FIG. 2 is a schematic diagram illustrating several types of movement path planning
for a wall-climbing robot.
FIG. 3 is a schematic diagram illustrating a spatial pose model of a wall-climbing
robot during a working process.
FIG. 4 is a schematic diagram illustrating stress analysis.
FIG. 5 is a schematic diagram illustrating a path for a robot to start automated operation
according to a current angle.
FIG. 6 is a schematic diagram illustrating stress analysis of automated operation
of a robot.
FIG. 7 is a schematic diagram illustrating stress analysis of automated operation
of a robot after compensation.
FIG. 8 is a schematic diagram illustrating a path of a robot performing automated
operation according to an offset angle.
FIG. 9 is a schematic diagram illustrating steering of wheel sets on two sides of
a robot.
FIG. 10 is a schematic diagram illustrating lane changing of a robot.
Detailed Description of Embodiments
[0021] In order to make the purposes, technical solutions and advantages of embodiments
of the present application clearer, the technical solutions in the embodiments of
the present application will be described clearly and completely below in conjunction
with the accompanying drawings of the present application. Apparently, the embodiments
described are some embodiments of the present application, but not all of embodiments.
Based on the embodiments of the present application, all other embodiments obtained
by those skilled in the art without involving any creative labor are within the scope
of protection of the present application.
[0022] Since a traditional robot is controlled by an operator using a wireless remote controller
to control the movement, lane changing and straight walking of the robot and the operator
is required to continuously operate the robot in the whole operation process of the
robot, the time and energy of personnel are greatly consumed and the labor cost is
increased. The solution of the present disclosure is used for solving the problems
above, and by means of the solution, the robot implements automated operation according
to path planning, straight walking and automated lane changing, the operator is freed
from frequently operating the remote controller and performing real-time monitoring,
and the robot is more intelligent.
[0023] A path planning method of the present disclosure includes the following steps.
[0024] Step 1, establishing a spatial pose model of a wall-climbing robot during a working
process.
[0025] FIG. 3 is a schematic diagram illustrating a spatial pose model of a wall-climbing
robot during a working process, where an OXYZ coordinate system is a ground coordinate
system and an OXYZ coordinate system is a ship wall surface coordinate system. In
FIG. 3, β is an included angle between a wall surface of a ship and a vertical plane.
According to an actual situation of the wall surface, it can be known that 0 ≤β≤ 90.
[0026] Step 2, performing statics analysis on the wall-climbing robot, and decomposing a
resultant force G of gravity of the wall-climbing robot and gravity of a load borne
by the wall-climbing robot to obtain components as follows:

where, by analyzing effects of the gravity components in the OXYZ coordinate system,
it can be known that Gz in a Z axis direction causes the wall-climbing robot to have
a trend of sliding down on the wall surface of the ship, the gravity components G
Y and Gz and a recoil force of a water jet will also produce an overturning moment,
especially in a situation that universal wheel(s) of the robot may face upwards, that
is, the magnetic force of the universal wheel(s) may be far less than the magnetic
force of driving wheel sets, the wall-climbing robot has a risk of flipping vertically
away from the wall surface, so that the posture with the universal wheels facing upwards
should be avoided in path planning.
[0027] Step 3, performing kinetics analysis on the wall-climbing robot, and analyzing a
crawling capability and a steering capability of the wall-climbing robot.
[0028] Crawling movement modes of the wall-climbing robot on the wall surface of the ship
is divided into a vertical mode and a horizontal mode.
[0029] Where, the vertical mode includes vertical upward movement and vertical downward
movement, a crawling robot in the vertical upward movement needs to overcome resistance
moments in identical directions, that is, a resistance moment caused by the gravity
of a body of the robot and the gravity of a load, and a resistance moment caused by
friction of the wheel sets; and when the speed is constant, a resistance moment of
the wall-climbing robot in the vertical upward movement is greater than a resistance
moment in the downward movement.
[0030] FIG. 4 is a schematic diagram illustrating stress analysis, where Gz represents a
component of a sum of the gravity of the body of the wall-climbing robot and the gravity
of the load borne by the wall-climbing robot along a z axis in the OXYZ coordinate
system, M represents a friction force of the wheel sets when the wall-climbing robot
moves upwards, M' represents a friction force of the wheel sets when the wall-climbing
robot moves downwards, F represents a driving force when the wall-climbing robot moves
upwards, and F' represents a driving force when the wall-climbing robot moves downwards.
[0031] According to the stress analysis in FIG. 4, in the vertical mode, the wall-climbing
robot can walk straight only by keeping a crawling angle unchanged. The wall-climbing
robot is equipped with an inertial measurement unit (IMU) module.
[0032] The vertical mode is implemented by the following steps:
step 301, manually adjusting the wall-climbing robot to a vertical posture, and recording
a current feedback angle α of the IMU module; and
step 302, step 302, setting a walking distance and a lane changing width of the wall-climbing
robot, and starting, by the wall-climbing robot, automated operation according to
the current feedback angle, with a completed operation area being S*L*N; where S represents
a crawling distance, L represents the set lane changing width, and N represents a
number of lane changing. FIG. 5 is a schematic diagram illustrating a path for a robot
to start automated operation according to a current angle.
[0033] The horizontal mode includes horizontal forward movement and horizontal backward
movement, and in horizontal movement of the crawling robot, the crawling robot needs
to overcome resistance moments in two directions, that is, the resistance moment caused
by the gravity of the body of the crawling robot and the gravity of the load, and
the resistance moment caused by the friction of the wheel sets. FIG. 6 is a schematic
diagram illustrating stress analysis of automated operation of a robot, where Gz represents
the component of the sum of the gravity of the body of the wall-climbing robot and
the gravity of the load borne by the wall-climbing robot along the z axis in the OXYZ
coordinate system, M represents a friction force of the wheel sets when the wall-climbing
robot moves upwards, M' represents a friction force of the wheel sets when the wall-climbing
robot moves downwards, F represents a driving force when the wall-climbing robot moves
upwards, and F' represents a driving force when the wall-climbing robot moves downwards.
[0034] According to the stress analysis in FIG. 6, in the horizontal mode, due to the influence
of the gravity Gz, the robot undergoes a tail falling phenomenon during crawling,
and the degree of tail falling when moving forward is different from the degree of
tail falling when moving backward. Therefore, an upward force F
Z is needed for compensation to balance the influence of Gz, and the following technical
implementation solution is proposed.
[0035] FIG. 7 is a schematic diagram illustrating stress analysis of automated operation
of a robot after compensation, where Q represents a resultant force of a driving force
and a friction force when the robot moves forward, F
Z represents a component of the resultant force in the z axis direction, F
X represents a component of the resultant force in an x axis direction, and α is a
set offset angle.
[0036] According to the stress analysis in FIG. 7, a force balance equation of the robot
can be listed as follows:

[0037] In a practical situation, working conditions of each ship are different, and a value
of α is directly influenced by a paint film material, a corrosion degree, marine life
and various types of iron rust. Therefore, during an actual operation, it is necessary
to measure the value of α in advance.
[0038] The horizontal mode is technically implemented by the following steps:
step 301', manually adjusting a crawling robot to a horizontal posture, and recording
a current feedback angle α1 of the IMU module;
step 302', allowing the crawling robot to move forward a set crawling distance S,
and recording a current feedback angle α2 of the IMU module;
step 303', calculating a difference between the two angles αf = α2 - α1, and taking αf as an offset angle set for the crawling robot moving forward the distance S;
step 304', manually adjusting the crawling robot to the horizontal posture corresponding
to the feedback angle α1 again;
step 305', allowing the crawling robot to move backward the set distance S, and recording
a current feedback angle α3 of the current IMU module;
step 306', calculating a difference between the two angles αb = α3 -α1, and taking αb as an offset angle set for the crawling robot moving backward the distance S; and
step 307', performing automated operation, by the crawling robot, according to the
offset angles αf and αb measured at two times, with an operation area being S*L*N, where S represents the
crawling distance of the robot, L represents the set lane changing width, and N represents
the number of lane changing. FIG. 8 is a schematic diagram illustrating a path of
a robot performing automated operation according to an offset angle.
[0039] When the above solution is realized, the wall-climbing robot is involved in steering
movement during a working process, the action is realized by differential motion of
driving wheels of the wall-climbing robot, and sideslip occurs when a driving wheel
on one side rotate fast and a driving wheel on the other side rotates slowly, so as
to perform the steering movement. A rotation speed and a rotation radius of the wall-climbing
robot during a steering process are also codetermined by movement directions and speeds
of the driving wheels, and the rotation radius directly determines a lane changing
distance of the wall-climbing robot. When speed directions of two driving wheels are
identical, speed directions of wheel sets on two sides are identical, and a rotation
center is located on an outer side of the wall-climbing robot; and when the speed
directions of the two driving wheels are opposite, the speed directions of the wheel
sets on the two sides are opposite, and the rotation center is located on an inner
side of the wall-climbing robot.
[0040] FIG. 9 is a schematic diagram illustrating steering of wheel sets on two sides of
a robot. In FIG. 9, a point a, a point b and a point c are centers of the wheel sets
on two sides and the body of the robot respectively, with O
1 representing a center of first steering of the robot and O
2 representing a center of second steering of the robot. As shown in Part a of FIG.
9, when the speed directions of the wheel sets on the two sides are identical, the
following formula is obtained:

when the speed directions of the wheel sets on the two sides are opposite, the following
formula is obtained:

where, the point a, the point b and the point c are the centers of the wheel sets
on the two sides and the body of the wall-climbing robot, r represents a steering
radius of the wall-climbing robot, which is half of the lane changing distance L,
V
a and V
b are speeds of the wheel sets on the two sides of the wall-climbing robot, V
c is a speed of the body of the wall-climbing robot, r is the steering radius of the
wall-climbing robot, and B is a distance between the point a and the point b.
[0041] FIG. 10 is a schematic diagram illustrating lane changing of a robot. The implementation
of lane changing by the wall-climbing robot specifically includes:
calculating the steering radius r of the robot according to the set lane changing
distance L, so as to calculate the speeds Va and Vb of the wheel sets on the two sides of the wall-climbing robot for first steering;
and
starting, by the wall-climbing robot, second steering when a rotation angle of the
first steering reaches 90 degrees, and rotating 90 degrees again in an opposite direction
of the first steering to complete a lane changing action.
[0042] According to the present disclosure, the advantages of Z-shaped (N-shaped) and zigzag
path planning are integrated, operation steps for lane changing are reduced, an overlapping
region is reduced and the operation efficiency is improved. Above all, the automated
operation is realized, and does not rely on the experience of the operator. The tail
falling phenomenon is avoided by rotating a certain compensation angle, so that the
robot can walk in a horizontal line instead of a previous curve in the horizontal
mode, and inside path navigation and automatic lane changing can be better realized.
[0043] The preferred embodiments of the present disclosure have been described in detail,
however, the present disclosure is not limited to the specific details of the above
embodiments, and various simple modifications may be made to the technical solution
of the present disclosure within the technical idea of the present disclosure, and
these simple modifications are all within the protection scope of the present disclosure.
[0044] In addition, it should be noted that the various technical features described in
the above specific embodiments may be combined in any suitable manner without conflicts,
and in order to avoid unnecessary repetition, various possible combination modes of
the present disclosure are not explained separately. In addition, various embodiments
of the present disclosure can also be arbitrarily combined, as long as they do not
violate the idea of the present disclosure, which should also be regarded as the disclosure
of the present disclosure.
1. A path planning method for a wall-climbing robot,
characterized in that the method comprises following steps:
step 1, establishing a spatial pose model of a wall-climbing robot during a working
process;
step 2, performing statics analysis on the wall-climbing robot, and decomposing a
resultant force G of gravity of the wall-climbing robot itself and gravity of a load
borne by the wall-climbing robot;
step 3, performing kinetics analysis on the wall-climbing robot, and analyzing a crawling
capability and a steering capability of the wall-climbing robot; and
step 4, performing path planning according to analysis results of the crawling capability
and the steering capability;
wherein the analyzing the steering capability of the wall-climbing robot in step 3
specifically comprises:
codetermining a rotation speed and a rotation radius of the wall-climbing robot during
a steering process by movement directions and speeds of driving wheels, wherein the
rotation radius directly determines a lane changing distance of the wall-climbing
robot;
when speed directions of two driving wheels are identical, speed directions of wheel
sets on two sides are identical, and a rotation center is located on an outer side
of the wall-climbing robot;
when the speed directions of the two driving wheels are opposite, the speed directions
of the wheel sets on the two sides are opposite, and the rotation center is located
on an inner side of the wall-climbing robot;
when the speed directions of the wheel sets on the two sides are identical, a following
formula is obtained:

when the speed directions of the wheel sets on the two sides are opposite, a following
formula is obtained:

wherein, a point a, a point b and a point c are centers of the wheel sets on the two
sides and a body of the wall-climbing robot, r represents a steering radius of the
wall-climbing robot, which is half of the lane changing distance L, Va and Vb are speeds of the wheel sets on the two sides of the wall-climbing robot, Vc is a speed of the body of the wall-climbing robot, r is the steering radius of the
wall-climbing robot, and B is a distance between the point a and the point b;
wherein implementation of lane changing by the wall-climbing robot specifically comprises:
calculating the steering radius r of the robot according to the set lane changing
distance L, so as to calculate the speeds Va and Vb of the wheel sets on the two sides of the wall-climbing robot for first steering;
and
starting, by the wall-climbing robot, second steering when a rotation angle of the
first steering reaches 90 degrees, and rotating 90 degrees again in an opposite direction
of the first steering to complete a lane changing action;
wherein the analyzing the crawling capability of the wall-climbing robot in step 3
specifically comprises: dividing crawling movement modes of the wall-climbing robot
on a wall surface of a ship into a vertical mode and a horizontal mode;
wherein the vertical mode is implemented by following steps:
step 301, manually adjusting the wall-climbing robot to a vertical posture, and recording
a current feedback angle α of an inertial measurement unit module; and
step 302, setting a walking distance and a lane changing width of the wall-climbing
robot, and starting, by the wall-climbing robot, automated operation according to
the current feedback angle, with a completed operation area being S*L*N, where S represents
a crawling distance, L represents the set lane changing width, and N represents a
number of lane changing;
wherein the horizontal mode is technically implemented by following steps:
step 301', manually adjusting a crawling robot to a horizontal posture, and recording
a current feedback angle α1 of the inertial measurement unit module;
step 302', allowing the crawling robot to move forward a set crawling distance S,
and recording a current feedback angle α2 of the inertial measurement unit module;
step 303', calculating a difference between the two angles αf = α2 - α1, and taking αf as an offset angle set for the crawling robot moving forward the distance S;
step 304', manually adjusting the crawling robot to the horizontal posture corresponding
to the feedback angle α1 again;
step 305', allowing the crawling robot to move backward the set distance S, and recording
a current feedback angle α3 of the current inertial measurement unit module;
step 306', calculating a difference between the two angles αb = α3 -α1, and taking αb as an offset angle set for the crawling robot moving backward the distance S; and
step 307', performing automated operation, by the crawling robot, according to the
offset angles αf and αb measured at two times, with an operation area being S*L*N, where S represents the
crawling distance of the robot, L represents the set lane changing width, and N represents
the number of lane changing.
2. The method of claim 1, wherein the vertical mode comprises vertical upward movement
and vertical downward movement; the crawling robot in the vertical upward movement
needs to overcome a resistance moment caused by the gravity of the body and the gravity
of the load of the robot and a resistance moment caused by friction of the wheel sets;
and when the speed is constant, a resistance moment of the wall-climbing robot in
the vertical upward movement is greater than a resistance moment in the downward movement.
3. The method of claim 1, wherein the horizontal mode comprises horizontal forward movement
and horizontal backward movement; and in horizontal movement of the crawling robot,
the crawling robot needs to overcome a resistance moment caused by the gravity of
the body and the gravity of the load of the crawling robot and a resistance moment
caused by friction of the wheel sets.
4. The method of claim 1, wherein in the horizontal mode, due to an influence of gravity
Gz, an upward force Fz is needed for compensation; and
in the horizontal mode, a force balance equation of the crawling robot is as follows:

where Q represents a resultant force of a driving force and a friction force when
the robot moves forward, FZ represents a component of the resultant force in a z axis direction, FX represents a component of the resultant force in an x axis direction, α is a set
offset angle, M represents a friction force of the wheel set when the wall-climbing
robot moves upwards, and F represents a driving force when the wall-climbing robot
moves upwards.